Suction cleaner



Fes. 7, 1939. Bl Q BECKER 2,146,006

SUCTION CLEANER Filed sept. 2e. 1936 s sheets-sheet 1 INVENTORernardecier ATTORNEY IB, C. BECKER sUcTIoN CLEANER Feb. 7, 1939;

Filed Sept. 28, 1936 l 3 Sheets-Sheet 2 vIa/ 287 faq .lia fifa lN VE NTC R 3er/mrd C'. ecker ATORNEY B. C. BECKER SUC'IION CLEANER Feb. l 1,.1939'.

Filed Sept. 28. 1936 3 Sheets-Sheet 3 INVENTOR 19e/ward 6. eekerATTORNEY Patented Feb. 7, 1939 UNITED STATES sUc'rloN CLEANER.

Bernard C. Becker, Canton, Ohio, assignor to The Hoover Company, NorthCanton, Ohio, a corporation of Ohio Application September 28, 1936,Serial No. 102,883

15 Claims.

This invention relates to improvements in suction cleaners and moreparticularly to an adjusting mechanism for suction cleaners whereby theheight of the nozzle may be promptly and 5 properly adjusted to thatbest suited to the character of the particular oor covering to becleaned.

It has been common practice heretofore to provide suction cleaners withnozzle height adjusting devices which are manually operated, as by the lturning of a knob in one direction or the other, l to raise or lower thenozzle to the height judged by the operator to be proper and accordingto an indicator which registers high, low or medium.' 4

Were cleaners only operated upon bare floors or hard surface coverings,such as linoleum, no adjustment of the nozzle height would be necessary.But, since the greater part of the work is performed on carpets andrugs, the need for adjust- SZOVing the height of the nozzle is essentialto effective results, due primarily to the fact that there is more orless penetration of the "supporting wheels of the cleaner into thecarpet nap, depending on the length, thickness and texture of the pileand, in some but lesser degree, upon y the resiliency, texture and weaveof the backing or foundation of the carpet. Obviously then, ,there is aproper and correct nozzle height adjustment for each kind and grade ofcarpet or tu rug so that there is a possible range of adjustment from abare oor to a verysoft and thick Velvet or Chinese rug.v Consequently,while the average operator can approximate the proper change in nozzleheight adjustment in passing 35j from one type of floor surface coveringto another,

' it is nevertheless largely a matter of guesswork, if, indeed, theadjustment is not neglected altogether. because of the physical eiortinvolved. The primary Object of the present disclosure is toprovide anozzle height adjusting mechanism which is automaticin its`operation, tothe exten't that it sets or regulates itself to the particular characterofthe door covering tobe cleaned, alrthough it does involve the manualoperation of fr pressirg clown and then releasing a foot pedal. And inthis'connection,-it should be pointed out that thebroad concept of thepresent disclosure, constitutes the subject matter of aicopending-application filed August 15, 1936, and-bearing'Serial" Number 96,222.Hence, a further object 'of the'present' invention is to incorporatecertain Aimprovements in' the so-called automaticnozzle height adjustingmechanism among'which maying feature, the nature of which may be brieyexplained atgthis point:

The fundamental and distinctive feature of the automatic nozzle heightadjustment is the provision of means whereby upon wheeling the suctioncleaner onto any oor covering tov be cleaned, the pressure of the footupon an operating lever momentarily disengages the nozzle carryingportion of the cleaner from the supporting means, thus allowing thenozzle to drop into contact with the surface of the floor covering andwhich for the present may be assumed to be any ordinary grade of carpet.The nozzle, presenting a somewhat extended flat surface arca, does notsink into or penetrate to any appreciable depth the nap or carpet pile,consisting as it does of a multiplicity of ne iibers and, as aconsequence, the nozzle comes. to rest in contact with the true carpetsurface, namely, the tips ofthe upstanding fibers, whereas thesupporting wheels of the cleaner penetrate into the carpet nap under theVweight of the cleaner. Thus it follows that regardless of the type ofcarpet surface, the act of lowering the nozzle into contact with thefloor covering, establishes a plane coinciding with that determined bythe tips of the carpet bers and it is from that plane that the correctheight of the nozzle: should be determined, regardless of the depth towhich the supporting wheels may sink into the carpet. Thus, if thecorrect nozzle elevation is fixed at' say inch, then this adjustmentwill be automatically established whenever the operator actuates theadjusting mechanism by successively depressing and releasing the footpedal. And this is exactly what the adjusting mechanism of the previousdisclosure accomplishes, namely, the elevating of the nozzle a xeddistance yabove the plane established by its contact with the carpetnap. But being a xed adjustment, it cannot compensate for varyingthicknesses or depths of nap in different carpets or rugs.A To explain:It is apparent that the supporting wheels of a. cleaner will sink intothe nap of a soft` thick piled carpet or rug to a much greater depththan they will into the nap of a thin andrela'tively short pile carpetand hence it follows, that in order to' obtain the correct nozzleadjustment the yamount of nozzle elevation must be greater in the caseof a thick and soit piled carpetas compared toa 50 relatively stiff andshort nap carpet.v

And itis this feature that `is referred to as the so-called compensatingtype of automatic nozzle adjusting mechanism and marks the` distinctionbetween they present and' the `previous disclosurewherein theelevation-of the nozzle is ilxed and constant regardless of thevariations in the thickness of the carpet pile. And in this connection.it might be added that in the average home and under ordinary conditionsthere may not be suflcient difference in carpet textures to make thecompensating feature of vital importance. On the other hand, there aremany homes and establishments where a Wide Variety of carpets and rugsare to be found and hence, for the correct and proper setting for thenozzle over a comparatively wide range of operating conditions, thecompensating type of automatic nozzle adjustment is of adeniteadvantage.

With the foregoing introductory matter, a preferred embodiment of theinvention will now be discussed in detail with reference to theaccompanying drawings, in which,

Figure 1 is a general view in side elevation of a suction cleaner with aportion of its side wall removed to show the general assembly of theimproved automatic nozzle height adjusting mechanism. A

Figure 2 is a'bottom plan view of the suctionl cleaner showing thesupporting carriage for the cleaner` casing and the nozzle adjustingmechanism associated therewith.

Figure 3 is a view in vertical section taken on line 3 3 of Figure 2,showing the adjusting mechanism in elevation from the opposite lside.

Figurei is a view in side elevation corresponding to Figure 1 showin-gvthe nozzle in its lowered position in contact with the .carpet surfaceand the nozzle height adjusting mechanism' immediately prior to vthereleasing of the foot pedal from its depressed position. g

Figure 5 is a perspective view of the supporting chassis removed fromthe cleaner and showing the assembly of the nozzle adjusting mechanismtherewith, and

Figure 6 is a detail view in vertical section through a portion of theadjusting mechanism as taken on line 6 6 of Figure 2. i

Referring to the cleaner in its general aspects, the same comprises amain casing I, having a nozzle portion 2, extending transversely of itsforward end and having the form of an elongated chamber with adownwardly facing opening. The casing extends rearwardly from the nozzleportion, gradually converging to a rearwardly opening flanged outletconnection' 3 to which is attached a dirt receptacle in the form of afabric bag 4. Centrally of the casing I is a circular fan chamber 5,visible from the under: side thereof, (Figure 2) and enclosing a fan 6,having direct driving connection with a motor (not shown) enclosedwithin a domelike cover or hood 1 surmounting'the casing I. The inlet toy the fan chamber has the form of a circular opening or eye 5a locatedcentrally of its bottom wall and concentric withithe vertical axis ofthe fan and its driving motor. Surrounding `the rear Y halfA of the fanleye 5a and extending forwardly towards the nozzle portion 2*,f`with aslight outward'are is a depending wall 8 curving abruptly through aright angle as it approaches the-nozzle and forming ltherear wallsegments 8a, 8a, thereof at itsouter ends. -This 'dependingwall formsthe sides of la passageextending forwardly and communicating with theinterior of the nozzle 2,

said passage beingclosed at its-bottom by a plate 9, having an upwardlyfacing-marginal groove- 9a. bearing against the bottom edge of the walland suitably lined with *a resilient material 'to form an'air tightseal.v Thisbottom plate `9 is shaped to conform with the outline of thewall 8, and preferably comprises as'an integral part thereof, the bottomplate I0 which forms the suction mouth of the nozzle 2, consisting ofnarrow lips surrounding the elongated rectangular shaped mouth. Y.

Within the nozzle chamber and immediately above the suction mouth islocated a rotating agitator I I, consisting of a cylindric shell havingbrush elements IIa, Ila, arranged lengthwise thereof and helicallyarranged beater elements IIb, IIb. The bottom plate 9 is removable touncover the nozzle chamber and the passage leading rearwardly therefrom,for access to the agitator as well as a drive belt I2 for the agitatorenclosed Within the passage from the nozzle chamber to the fan chamberand extending from a pulley I3 carried at the lower end of the fan shaftto a pulley groove IIc midway between the ends of the agitator II andprotected by a guard member I4, extending transversely of the suctionmouth, as clearly shown in Figure 2.

Again referring to the main casing I, with its centrally disposedcircular fan chambery 5, it will be noted that along the edges of thecasing and extending rearwardly from the ends of the nozzle 2 aredepending curvilinear walls Ia, Ia, and between these depending marginalwalls and the side walls of the fan chamber 5, are cavities or hollowspaces which have a depth substantiallyv equal to the height of thecasing I itself. It is within these cavities and enclosed by themarginal side walls Ia, Ia, of the casing, that are located the wheeledsupport for the casing and the nozzle adjusting mechanism associatedtherewith.

Referring iirst to the supporting means for the cleaner, vthe samecomprises a U-shaped chassis or carriage I5 carrying a pair of frontcarrier Wheels I6, I6 located just inwardly from the sidesautomatic-adjustable connection between 'the forward end of the chassisand the casing, including a foot operated pawl and ratchet mechanism,which functions to bring about the desired tilting of the cleaner bodyon theewheeled chassis to maintain the correct elevationof the'nozzle,

above the carpet surface.

Referring particularly to the form and mounting of the chassis orcarriage I5. yit has the form of a U-shaped casting disposedsymmetrically beneath the cleaner casing. I with its base portion I 5aextending transversely *at the .real-l at:

the casing and its two arms or branches |52), 'f

extending forwardly within the -cavities formed between the outermarginal side walls Ia, 'la and the circular outer wall of the fanchamber 5. A pivot bolt I8 depends vertically from the bottom wall ofthe fan chamber 5 entersa downwardly facing socket I5c at .the center ofthe base portion I5a of the chassis frame I5.; A nuty YI8a mounted katthe lower end ofthe pivotvbolt I8 supportsa coil spring vI Swith itsretaining collar bearing against the pper vend of the, socket yI5c,forms a somewhat resilientplvotal o r swivel connection between thecleaner casing I and the 19a', said spring surroundlngvsaid pivot `pinand l Figure 3.

otally mounted on bearing pins 21, 21 supported.

However, in order to limit the movement between the cleaner casing I andthe chassis I5, a pair of upwardly facing V-shaped channels 20, 20 areformed in the upper face of the central or base portion Ia and onopposite sides of the bolt receiving socket I5c and engaged bycorresponding knife-edge projections or flanges 2 I, 2I

cast integral with the cleaner casing and depend-v ing-from the undersurface of the fan chamber. Manifestly, the combination of the springbolt connection and the knife-edge flanges rocking in the V-shapedchannels in the chassis frame aords a solid and substantial mounting forthe casing andyet permits the necessary tilting for obtaining thedesired nozzle adjustment. And extending rearwardly from the baseportion I5a of the .chassis frame I5, is a pair of spaced arms 22, 22which form a supporting-bracket for an axle I1a on which are journaledthe rear wheels or casters I1, I1.`

Now, following the -forwardly extending arms I5b, I5b of the chassisframe I5, outwardly to their forward ends it will be noted, as shown inFigure 2, that they terminate just lrearwardly of the nozzle 2, in theform of downwardly andforwardly extending fork members 23, 23,supporting at their lower end, bearing shafts 24, 24 on which arejournaled the front carrier wheels I6, I6. f

Carried -by the chassis I5 just rearwardlyof and above the front wheelsupporting members 423, 23 is an inverted U-shaped bail member 25 whichforms the lower extremity of the handle of the cleaner and, straddlingthe dome-like cover 1, projects through longitudinal slots 26, 26 in thetop wall of the casing I with its ends pivby bosses 21a, 21a, formedintegral with the end portions of the chassis frame I5 and projectinglaterally and inwardly therefrom (Figure 5). Thus the cleaner handle iscarried by the wheeled chassis and quite independently of the casing I.

Associated with the handle bail 25 and mounted adjacent the end of oneof' the arms I5b of the chassis frame I5, is a handle position controldevice which serves to restrain the handle from free swinging movementand to define its extreme positions as well as its intermediate orworkingv range. This device is already in common use, except that in itspresent application, the action is between a cam sector carried by thehandle bail and a spring pressed roller mounted on the chassis insteadof on the cleaner casing. Thus, as clearly shown in Figure 3, the camsector 28 is fixed to the end portion of the handle bail 25 on the sameside of the cleaner as the nozzle adjusting mechanism, said sectorprojecting below the bail end pivot and having along its arcuate loweredge threeA notches, the endmost notches 28a being semi-circular inshape and the intermediate notch 28h being somewhat elongated.4 Nowbearing edgewise against the notched edge of the sector 28, is a camroller 29 carried at the free end of a bell crank lever 30 journaled ona pivot pin 3| supported at the lower extremity of a depending web 3Iaintegral with the chassis frame I5, Figure 4. The upwardly projectingarm 30a of the bell crank lever 30, forms an abutment for one end of acompression spring 32, suitably supported on the chassis frame I5.Manifestly, the spring acting through the lever 30, holds the roller 29against the edge of the control sector 28, so that while it is possibleto shift the handle from one position to another quite readily, thespring-pressed cam roller 29 holds the handle in that position.

Referring now to the improved nozzle height adjusting mechanism,attention is first directed to the fact that as thus far described thebody of the cleaner is pivotally connected to its chassis with only theweight distribution to hold the nozzle from being tilted. But with theintroduction of an adjustable supporting member between the two, theraising and lowering of the nozzle is accomplished.

This adjustable supporting member is carried by the carriage I5 andconsists of a somewhat irregular shaped ratchet lever 33 pivotallymounted on a bearing pin 34 carried at the forward and upper edgeportion of the left hand arm I5a of the chassis, as viewed in Figure 2.Projecting beyond its pivot, this lever terminates in a pointed orwedge-shaped cam member 33a, which presents an inclined cam face havingbearing contact with a correspondingly inclined abutment plate 35extending diagonally of the corner angle formed at the junction of thetop wall of the'casing I and the vertical rear wall segment 8a of thenozzle chamber. This abutment plate 35 is preferably provided with aflat cam face having contact with a slightly convexed cam member 33d atthe upper end of the ratchet lever 33, but as presently will be seen theangularity and contour of these cam faces may be varied, depending onthe desired vertical displacement of the casing during a given angle ofrocking movement of the lever. Thus it may be assumed for the purpose of'this discussion that the weight of the cleaner body is transmitted tothe chassis through the abutment plate to the lever 33 and thence to thechassis, and that by rocking said lever 33, the action of the cam member33a raises or lowers the forward or nozzle end of the casing I.

Continuing the description of the ratchet lever 33, the same extends ina general downwardly and rearwardly inclined direction from its pivotpin 34 and as it`approaches its rear end, diverges abruptly into aratchet sector 36 having somewhat the shape of a sh tail with a slightlycurved edge in which are cut a series of ratchet teeth 36a.

Also pivotally mounted on the same pin 34 that supports the ratchetlever 33 upon the chassis, is another somewhat irregularly shaped lever31 having somewhat the characteristics of a lever of the bell-cranktype. From its point of pivotal mounting on the pin 34, this secondlever 31 has a forwardly disposed arm 31a which extends in a generaldownward direction and another arm 31h also extending downwardly, but ina more rearwardly direction with a slight upturn at its extremity. l

Referring to Figures l and 2, it will be noted that the forwarddepending arm 31a of the bell crank vlever 31 lies just inside of theratchet lever 33 and that at its lower end supports a pivot crank lever31 actually straddle the pawl lever 33, as shown in Figure 6. Returningto the pawl lever 39, its outerl and free end which extends a CFItoothed edge of the ratchet sector 36, with which it is adapted to havea pawl and ratchet connection.

Acting on the pivoted pawl lever 39 is a torsion spring 40 which' iscoiled around. an enlarged bearing portion of the pivot pin 38 andhaving straight end portions which cross each other at right angles, theuppermost end being caught by a hooklike lug 4I on the lower edge of thelever 31 and the other end terminating in a hooked extremity engagingthe lower edge of the pawl 39. The torsion spring40 th-us exerts aconstant force upon the pawl lever tending to swing it upwardly and in acounterclockwise direction' and the dog 39a at its free end upwardly andaway from the toothed edge of the ratchet sector 36. The actual movementof the pawl lever 39 however, is very limited; in fact, 'its extremeswinging movement is conned to an arc of a few degrees, as will be seenby comparing Figuresv l and 4, wherein the dog 39a strikes the undersideof the chassis I5 to limit upward movement of the pawl lever 39.

Now, with the pawl dog l39a. engaging the ratchet sector 36, it followsthat the levers 31 and 33 become united and oscillate together, and

if-movement is imparted to the bell crank lever 31 while so connectedwith the ratchet lever 33, this movement will be transmitted to thecasing I through the rolling contact between the edges of the wedgeshaped cam member 33a of the ratchet lever 33 and the inclined abutmentplate 35 on the casing I.

Now, the bell crank lever 31 is the primary moving member of thiscombination of interconnected levers and tov which a limited oscillatingor rocking movement is imparted through a foot actuated operating lever42 pivotally mounted intermediate its ends on the same bearing pin 3Ithat supports the handle position control lever 30. The forward andshorter arm 42a: of the operating lever is provided with a bifurcated orforked extremity which' has pivotal connection v with a pin 43 carriedat the end of.the rearwardly extending lever arm 31h of the bell cranklever 31, from its point of pivotal mounting on the under side of thechassis I5, the other arm of the operating lever 42 extends rearwardlyand is provided. at its extremity with a foot pedal 44 projectinglaterally and outwardly from beneath the depending marginal wall Ia, ofthe cleaner casing I as clearly shown in Figure 2.

The operating lever 42 normally assumes a horlzontal position being heldagainst depression by means of a coil spring 45 of the compression typecarried by the chassis and mounted in vertical position with aconnecting rod 46 extending axially through the spring and connected atits lower end with the operating lever and its upper end with anabutment plate 46a bearing upon the top of the spring. Thus thedepression of the l operating lever 42 is opposed by the spring 45Referring to Figure 1, it may be assumed` that n the cleaner has beenproperly adjusted as to nozzle height for a particular carpet or floorcovering and is about to be readjusted vfor another and a differentgrade of carpet to be cleaned.

Naturally, the carriage or chassis l rests upon 5 lthe carpet with thewheels sinking into the surface somewhat, the casing I assuming aslightly forward tilted position with the nozzle elevatedv a denitedistance above the carpet surface.

- Now, the position of the nozzle, it is to be noted,

is determined by the point at which the cam 33a contacts the abutmentplate 35. But it should be noted also that the actual distance thenozzle rocked, the angularity of the contact edge of the cam 33a will bechanged and again, if there is anyappreciable displacement between thecasing and the chassis there would be a corresponding shifting of thepoint of contact between these cam faces and the differential of thesevariable lfactors produces a third variable, namely, the distan thenozzle will be displaced from the chassis during anyadjusting operation.

'I'his will be better understood from vthe following description of thepart which the several levers play in the adjusting operation: Any givenposition of adjustment such as that shown in Figure 1, will illustratethe relative positions of the parts at the beginning of -an adjustingoperation. In the rst place, it will be noted that the pawl lever 39under the tension applied to it by the torsion spring is held in toothedengagement with the ratchet sector 36 and since the 40 y pawl lever iscarried by. the bell crank lever 3,1 and the latter'held against themovement by the operating lever 42 and its` spring 45, it follows that aconstant nozzle height adjustment will be maintained as long as therelative positions of the various parts of the adjusting mechanism arenot altered. v

But let it be lassumed that the cleaner is moved ontoy another and avery different type of carpet' surface and hence a readjustment of thenozzle height is necessary. To accomplish this the operator merelydepresses the foot lever 42 to its lowermost position as shown in Figure4, and then releases it whereupon it is returned to its normal positionby the spring 45. But during the down- '55 ward stroke of the operatinglever, several move- `ments take place andv these will now be considered intheir order or sequence:

First of all, the depression of the foot lever 42 l transmits a rockingmovement to the bell crank lever 31 in a counter-clockwise directionuntil the dog 39a strikes the underside of. theadjacent forwardlyextending side arm I5b of the chassis I5 and thus holds the pawl lever39 against further upward movement. But in the continued movement oroscillation of the bell-crank lever 31, the pawl lever is shiftedendwise` and in a rearward direction thereby effecting the disen-1gagement of the ratchet sector by the pawl dog 39a. This displacement ofthe pawl lever 39 re- 70 leases the ratchet lever v33 leaving the latterfree to oscillate under the weight of the cleaner casing exerted uponthe cam member 33a at its forward end and, with the release of theratchet sector 33, the cleaner casing tilts forwardly by gravity until75 the nozzle rests upon the carpet nap, that is, the surface defined bythe tips of the upstanding carpet fibers, since as already explained,the area of the lips surrounding the nozzle opening is sufiicientlylarge to prevent the appreciable penetration of the nozzle into thecarpet pile. Now, all of this action takes place during the depressionof the foot pedal and while it is being held momentarily in depressedposition by the operators foot, meantime the parts of the adjustingmechanism assuming the positions shown in Figure 4 until the foot leveris released.

Now, at this point let it be assumed that the carpet to which the nozzleheight is to be adjusted, is considerably thicker than that on which thecleaner had been previously operating, that is to say, the nap of thecarpet is considerably deeper' and more than that, the carpet fibers areconsiderably softer. This means of course, that the supporting wheels ofthe cleaner would sink into the nap of the carpet to a considerablygreater depth than they did into the nap of the y carpet which hadpreviously been operated upon,

from which it follows that the initial position of the nozzle would bemuch closer to the surface Y of the softer, thicker piled carpet than itwas Cil on the harder and shorter piled carpet. In other words, thenozzle height adjustment proper for the first carpet is entirelyimproper for the carpet upon which the cleaner is about to be operated.

Thus, it is because the supporting Wheels of a cleaner sink to a greateror lesser depth into the carpet nap depending upon the kind and textureof aparticular carpet or rug, that it is necessary to compensate forthis difference in wheel penetration by correspondingly varying theheight of nozzle elevation. And this is exactly what takes place uponthe completion of the adjusting operation by the release of the footlever 42. Now, to understand exactly what takes place, it should befirst explained that due to the pivotal connection of the cleaner casingwith its chassis, the relative movement between the nozzle and thecarriage is not so much a vertical displacement as a tilting of thecleaner casing about its pivotal mounting on the carriage, although forcon- .venience thisA relative movement may be assumed .being the resultof the cam 33a carried by the chassis rolling along the abutment plate35 on the casing.

Now, with this relationship in mind let it again be noted that for theprevious nozzle height adjustment, the contact between the cam 33a andthe abutment plate 35 was determined by the angular position of theratchet lever 33, which in turn was governed by `the particular ratchettooth 36a engaged by the pawl 39a.. But having transferred the cleaneronto another and entirely different type of carpet, the depressing ofthe foot lever 42 allows the nozzle to be lowered into contact with thecarpet surface but not to the same extent that it was during theprevious adjustment, due to the fact that the pile of the carpet is muchthicker and hence the nozzle is brought to rest at a'somewhat higherlevel than previously.

Now, due to the Obliquity of the line indicating the direction of therelative movement `between the casing and the chassis, the tiltingmovement of the casing when released by the depressing of the operatinglever is translated into the lengthwise rolling contact between the twocontacting faces of the abutment plate 35 and cam 33a from a point nearthe tip end of the cam inwardly toward the base of said cam. But thepoint at which these cam surfaces meet at the end of their rollingcontact will not be the same as it was during the preceding adjustingoperation because the nozzle is notv lowered to the same extent that itwas during the previous adjustment, and since the ratchet lever is freeto swing with the lowering of the nozzle, it follows that the point ofcontact between the two cam surfaces when the nozzle has come to rest onthe carpet, will be farther removed radially from the axis of rotationof the ratchet sector than it was to the commencement of thepreviousreadjusting operation. As a consequence, therefore, a different portionof the slightly convex edge of the cam 33a will have rolling contactwith the edge of the abutment plate 35 during the elevation of thenozzle and since the curvature of the convex edge of the cam 33a becomesincreasingly pronounced as it extends outwardly and is eccentric to thepivotal axis of the ratchet sector, the displacement of the nozzle willvary with the arc of contact between the two cam surfaces during eachadjusting operation.

This will be evident by considering the positions of the various partsas shown in Figure 4, and assuming again that the parts have momentarilycome to rest after the nozzle has, been lowered into contact with thecarpet surface. Immediately the foot lever begins its upward stroke, thebell crank lever 31 swings downwardly and forwardly in a clockwisedirection, this in turn imparting an endwise shiftingmovement to thepawl lever 39 carrying its dog 39a bodily forward and into contact withthe toothed edge of the ratchet sector 36. Now, the particular toothwhich is engaged by the pawl will not be the same one from which it wasreleased at the commencement of the preceding adjusting operation,because the ratchet sector has in the meantime been rocked or oscillatedinto a different angular position, and which has been determined by theposition of the nozzle in contact with the carpet surface. And finally,having engaged the pawl 39 with the ratchet sector 36, the continuedoscillation of the bell crank lever 31 carries the ratchet lever 33 withit throughout the remainder of the movement imparted to it by the returnstroke of the operating lever 42, this oscillating or rocking movementof the ratchet sector being translated `into a rolling contact betweenthe two cam surfaces which not only imparts a lifting movement to thecasing but controls the distance that the nozzle comes to rest above thesurface of the carpet. Obviously this control, entirely automatic in itsaction, is attributable wholly to the location of the point of contactbetween the two cam surfaces at the commencement of the elevatingmovement of the nozzle since it is this starting point that determinesthe angularity of the arc of rolling contact and hence the ensuing "liftof the nozzle.`

Obviously, it is possible to increase or decrease the amount of thenozzle elevation by varying the angularity of the cam edges or byredesigning or altering the various parts of the mechanism so that theratchet lever 33 will oscillate through a smaller or greater arc withoutchanging the stroke of the operating lever. Consequently, the particulardetails of design of the present disclosure may be variously modiedwithout departing from the spirit of the invention.

I claim:

l. In a suction cleaner having a casing provided with a nozzle and awheeled support adjustable relatively to said casing, means for loweringsaid nozzle into contact with the oor covering and subsequentlyelevating the same automatically above the surface thereof, and meansacting automatically to vary the elevation of said nozzle in directproportion to the depth said support sinks into the floor covering.

2. In a suction cleaner having a casing provided with a nozzle and awheeled carriagev having pivotal connection therewith, said casing beingtiltable on said carriage for regulating the height of said nozzle abovethe iioor covering to be cleaned, means for normally supporting saidcasing in a predetermined position of nozzle adjustment, mechanismvoperative to lower said nozzle into contact with the surface to becleaned and thence to elevate the same automatically to a predeterminedheight above said surface, and means associated with said nozzle heightadjusting mechanism to compensate for the penetration of the wheels ofsaid carriage into .the covering to be cleaned. Y v

3. In a suction cleaner having a casing provided with a nozzle and awheeled support pivotally mounted on said casing, and means foradjusting the height o f said nozzle above the carpet surface,comprising operator actuated mechanism operative to lower said nozzleinto contact with the carpet surface and thence to raise said nozzleautomatically lto a predetermined height above said surface, and meansassociated with said elevating mechanism for automatically compensatingfor the depth of penetration of the wheeled support into the nap of saidcarpet.

4. In a suction cleaner having a casing provided with a nozzle and awheeled suport pivotally connected therewith for relative verticaladjustment, a shiftable member carried by said support 'and normallysupporting said casing at a predetermined nozzle height and adapted tobe actuated to lower said nozzle into contact with the surface of thefloor covering/,and thence automatically to elevate said nozzle to apredetermined height above said surface, and means coacting with saidshiftable member to increase the subsequent elevation of said nozzle indirect proportion to the depth said Wheeled support penetrates thesurface of the :door covering.

5. In a suction cleaner having a casing provided with a nozzle and awheeled support pivotally l connected therewith for relative verticaladjustment, a shiftable cam member carried by said wheeled support andoperative to raise and lower, said nozzle, means normally acting tomaintain a predetermined nozzle' height adjustment and adapted toactuate said cam member to permit said nozzle to be lowered into acontact with the carpet surface and thence to be elevated automaticallyto a predetermined distance above said surface, and means forautomatically varying the elevation of said nozzle in direct proportionto the depth of penetration` of the Wheeled support into the nap of saidcarpet.

8. In a suction cleaner having a ,casing provided with a nozzle and aWheeled support having pivotal connection with said casing, and

means for adjusting said casing relative to said support to vary theheight of the nozzle above the carpet surface, ycomprising a leverpivotally mounted on said Wheeled support and having a cam contacting anabutment on said casing, said lever being operative in one direction tolower said nozzle into contact with the carpet surface from a givenposition of adjustment and inv the opposite direction to elevate saidnozzle automatically to a predetermined height above said carpetsurface, and means acting automatically to shift said cam and abutmentrelative to each other to increase the elevation of said nozzle indirect proportion to the depth the wheeled support penetrates the carpetnap.

'1. In a suction cleaner having a casing provided with a nozzle and awheeled support having pivotal connection with said casing, and meansfor adjusting said vcasing relative to said support to vary the heightof said nozzle above the carpet surface, comprising a lever pivotallymounted on said wheeled support and having a cam adapted to contact anabutment on said casing, means normally locking said lever in astationary position of casing adjustment, means for releasing said leverto permit said nozzle to drop into contact with the carpet surface andfor subsequently raising said nozzle automatically to a predeterminedheight above said carpet surface,

said cam being shiftable bodily with respect to said abutment and havinga predetermined convtour whereby the elevation of said nozzle 'lisgovvided with a nozzle and a wheeled support for disengage said pawl andratchet sector to permit said nozzle to drop into contact with thecarpet surface and subsequently to cause said-pawl to reengage saidratchet sector to raise said nozzle, the abutment contacting face ofsaid cam having a predetermined contour whereby the elevation of saidnozzle is governed by the point of contact of said cam and abutment whensaid nozzle is in contact with the carpet surface.

9. In a suction cleaner having a casing provided With a nozzle and awheeled support for said casing having pivotal connection therewith andmeans for adjusting the height of said nozzle above the surface of thecarpet to be cleaned, comprising a ratchet sector pivotally mounted onsaid wheeled support and normally supporting said casing from beneaththrough the medium of a cam of predetermined contour having bearingcontact with an abutment on said casing, an operating lever mounted onsaid wheeled support, a spring-pressed pawl carried by said operatinglever and normally engaging said ratchet sector to hold the latter instationary position, but shiftable in the movement of said operatinglever in one direction to release said ratchet sector and thereby permitsaid nozzle to drop into contact with the carpet surface and shiftablein another direction in the movement of said operating lever to itsinitial position to reengage said ratchet cleaned, comprising a ratchetlever pivotally mounted on said supporting frame and provided with atoothed sector and a camhaving bearing contact with an abutment on saidcasing, an operating lever pivotally mounted on said frame and having apawl adapted normally to engage thetoothed sector of said ratchet leverand shiftable bodily to release said sector in the movement of saidoperating lever in one direction, to thereby affect the lowering of saidnozzle into contact with the carpet surface and shiftable into aposition to reengage said sector in the movement of said operatingleverin the opposite direction and raise said nozzle, said abutment onsaid casing and said cam having coacting bearing faces of predeterminedcontour and angularity whereby the elevation of said nozzle varies withthe location of a point of contact of said cam with'said abutment whensaid nozzle is in contact with the carpet surface. y

11. In a suction cleaner having a casing provided with a nozzle and awheeled support for said casing including a frame pivotally connected tosaid casing-and having wheels journalled thereon, and means forAadjusting said casing relative to said support to vary the height ofsaid nozzle above the surface of the .carpet tobe cleaned, comprising aratchet lever pivotally mounted on said supporting'frame and providedwith a toothed sector and a cam having bearing y contact withan abutmenton the underside of said casing, an operating lever mounted on 'saidframe, a spring-pressed pawl carried by said operating lever andnormally engaging the toothed sector of said ratchet lever to maintainsaid casing in a predetermined position of adjustment, said operatinglever being shiftable in one direction to eilect the disengagement ofsaid ratchet sector by said pawl and the lowering of said nozzle intocontact with the carpet surface and in the opposite direction to effectthe reengagement of said ratchet sector by said pawl, and the raising ofsaid nozzle, said abutment and cam having `contacting surfaces of apredetermined contour and angularity whereby the .relative position ofsaid casing'and Wheeled support when said nozzle is in contact with thecarpet surface increases the subsequent elevation of said nozzle indirect proportion to the depth ofl penetration of said wheels into thecarpet surface.

12. In a suction cleaner having a casing provided with anozzle at itsforward end and a wheeled carriage pivotally connected to the undersideof said casing adjacent one end thereof, an adjustable member on saidcarriage normallysupporting said casing adjacent its opposite end,operating means acting to depress momentarily said casing supportingmember to permit said nozzle to drop into contact with the surface ofthe noorcovering, tension means for subsequently elevating said nozzleto a predetermined height above said surface and means for autocarpet.

matically adjusting the elevatiton of said nozzle to compensate for thevarying depth of penetration of the supporting wheels into carpets ofdifferent texture.

13. In a suction cleaner having a casing provided with a nozzle at itsforward end and a carriage pivotally connected to the underside of saidcasing adjacent its rear end and having supporting wheels adjacent theforward end thereof, an adjustable contact member on said carriagesupporting the forward portion of said casing with said nozzle above thesurface of the carpet and operator actuated ratchet mechanism operativeto depress momentarily said adjustable contact member to lower saidnozzle into contact with the carpet and including compensating meanswhereby the subsequent elevation of said nozzle is automaticallydetermined by the penetration of the supporting wheels into the carpetpile.

14. In a suction cleaner having a casing pro- "vided with a nozzle atits forward end and a wheeled carriage pivotally connected with theunderside of said casing, said connection being adjacent one endthereof, a ratchet lever carried by said Wheeled carriage and having acam supporting said casing adjacent the opposite end thereof, anoperating lever pivotally mounted on said carriage and having a springpressed pawl normally engaging a toothed sector on said ratchet lever tohold the same against displacement, said operating lever being shiftablein one direction to disengage said pawl from said sector, therebydropping said nozzle into ush contact with the surface of the floorcovering under the Weight of said casing, and tension means acting toreturn said operating lever in the opposite direction whereby saidratchet sector is reen- A gaged by said pawl to elevate said nozzle apredetermined. fixed distance above the surface of said oor coveringplus an amount equal to the depth of penetration of the wheels into thesame.

15. In a suction cleaner having a casing provided with the nozzle at itsforward end and a carriage beneath said casing and pivotally connectedadjacent the rear end thereof, a ratchet lever pivotally mounted onsaidcarriage and having a cam at one end supporting said casing anda toothedsector at its opposite end, an operating lever pivotally mounted on saidcarriage, a spring pressed pawl lever pivotally mounted on saidoperating lever and normally having toothed engagement with the sectorof said ratchet lever, tension means acting on said operating lever tohold the same in its normal position wherein the nozzle portion of saidcasing is supported above the carpet surface, said pawl member actingduring the movement of said operating lever in one direction to. effectthe release of said sector whereupon said nozzle is permitted to dropinto contact with the carpet surface and upon the subsequent release ofsaid operating lever and its return to its normal position under thetension of said spring to reengage said sector and thereby actuate saidcam to raise said nozzle a predetermined distance above the surface ofsaid floor .,covering, said cam and casing havingcontact carpet lsautomatically adjusted to compensate for the depth of wheel penetrationinto said BERNARD c. BECKER.

